/*
 * Copyright (c) 2011-2014 Pivotal Software, Inc.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.camunda.bpm.extension.reactor.projectreactor.support;

import org.camunda.bpm.extension.reactor.projectreactor.Event;

import java.util.function.Consumer;

/**
 * Simple {@link Event} implementation that attaches a callback to an {@link Event} and
 * passes it to a delegate {@link Consumer}.
 *
 * @param <T> the type of the event payload
 * @author Stephane Maldini
 */
public class CallbackEvent<T> extends Event<T> {
  private static final long serialVersionUID = -7173643160887108377L;
  final Consumer callback;

  public CallbackEvent(T data, Consumer callback) {
    this(null, data, callback);
  }

  public CallbackEvent(Headers headers, T data, Consumer callback) {
    this(headers, data, callback, null);
  }

  public CallbackEvent(Headers headers, T data, Consumer callback, Consumer<Throwable> throwableConsumer) {
    super(headers, data, throwableConsumer);
    this.callback = callback;
  }

  @Override
  public <X> Event<X> copy(X data) {
    if (null != getReplyTo())
      return new CallbackEvent<X>(getHeaders(), data, callback, getErrorConsumer()).setReplyTo(getReplyTo());
    else
      return new CallbackEvent<X>(getHeaders(), data, callback, getErrorConsumer());
  }


  /**
   * Trigger callback with current payload
   */
  @SuppressWarnings("unchecked")
  public void callback() {
    if (null != callback) {
      callback.accept(getData());
    }
  }
}
